package an;

public class Ref {

	int an = 9;

	private Ref() {
	};

	private static class B {
		private static final Ref instance = new Ref();
	}

	public static final Ref getinstance() {

		return B.instance;
	}

	public void A() {
		System.out.println("脚很疼。。");
	}

}